/* 整体布局 */
.study-container {
    display: flex;
    gap: 40px;
    margin-top: 40px;
}

/* 左侧侧边栏 */
.sidebar {
    width: 220px;
    position: sticky;
    top: 100px;
}
.nav-category {
    padding: 10px;
    cursor: pointer;
    border-bottom: 1px solid #eee;
}
.nav-category.active {
    color: #d7423a;
    font-weight: bold;
}

/* 内容区域 */
.content-area {
    flex: 1;
}

/* 搜索框 */
.search-box {
    display: flex;
    margin-bottom: 20px;
}
.search-box input {
    flex: 1;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px 0 0 4px;
}
.search-box button {
    padding: 10px 15px;
    background-color: #d7423a;
    color: white;
    border: none;
    border-radius: 0 4px 4px 0;
    cursor: pointer;
}

/* 资源列表 */
.resource-list {
    display: grid;
    gap: 20px;
}
.resource-item {
    background-color: #f9f9f9;
    padding: 20px;
    border-radius: 6px;
    transition: box-shadow 0.3s ease;
}
.resource-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
.resource-item h4 {
    margin-top: 0;
}
.resource-item p span {
    color: #555;
}
.btn.btn-primary {
    background-color: #d7423a;
    color: white;
    text-decoration: none;
    padding: 6px 12px;
    border-radius: 4px;
}
.btn.btn-primary:hover {
    background-color: #b5362e;
}